Hepatitis B virus infection in adolescents in a rural township—15 years subsequent to mass hepatitis B vaccination in Taiwan

Survey of hepatitis B virus infection status after 35 years of universal vaccination implementation in Taiwan

BACKGROUND AND AIMS

Hepatitis B virus (HBV) vaccination programs in Taiwan are one of the earliest programs in the world and have largely reduced the prevalence of HBV infection. We aimed to demonstrate the vaccination efficacy after 35 years and identify gaps toward HBV elimination.

METHODS

A total of 4717 individuals aged 1-60 years were recruited from four administrative regions based on the proportion of population distribution. Serum levels of hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc) levels were assessed. HBV viral load, genotypes and HBsAg 'ɑ' determinant variants were evaluated if indicated.

RESULTS

After 35 years of vaccination, the overall seropositivity rates for HBsAg and anti-HBc in Taiwan were 4.05% and 21.3%, respectively. The vaccinated birth cohorts exhibited significantly lower seropositivity rates for both markers compared to the unvaccinated birth cohorts (HBsAg: 0.64% vs. 9.78%; anti-HBc: 2.1% vs. 53.55%, respectively; p < 0.0001). Maternal transmission was identified as the main route of HBV infection in breakthrough cases. Additionally, increased prevalences of genotype C and HBsAg escape mutants were observed.

CONCLUSION

The 35-year universal HBV vaccination program effectively reduced the burden of HBV infection, but complete eradication of HBV infection has not yet been achieved. In addition to immunization, comprehensive screening and antiviral therapy for infected individuals, especially for pregnant women, are crucial strategies to eliminate HBV.

The effects of booster vaccination of hepatitis B vaccine on children 5-15 years after primary immunization: A 5-year follow-up study

The aim of this study was to evaluate changes in hepatitis B surface antibody titers (anti-HBs) after booster vaccinations in children aged 5-15 y and to provide suitable immunization strategies. A total of 2208 children were initially enrolled in screening, and 559 children were finally included. The participants were divided into 2 groups according to their pre-booster anti-HBs levels: Group I, <10 mIU/ml and Group II, ≥10 mIU/ml. Group I was administered 3 doses of booster hepatitis B vaccine (0-1-6 months, 10 μg), and Group II was administered 1 dose of booster hepatitis B vaccine (10 μg). The antibody titer changes were examined at 4 time points: 1 month after dose 1 and dose 3, and 1 year and 5 years after dose 3. The protective seroconversion rates at those points were 95.65%, 99.67%, 97.59% and 91.05% (p < 0.001), respectively, in Group I, and 100.00%, 99.87%, 99.66% and 98.21% (χ² = 6.04, p = 0.11), respectively, in Group II. The GMT in subjects aged 5-9 y were higher than that in subjects aged 10-15 y in both Group I and Group II at 1 month after dose 1, but no difference was observed at the other three time points. This study demonstrates that booster vaccination has a good medium-term effect. A booster dose for subjects with protective antibodies is not necessary but effective, and 3 doses of hepatitis B vaccination are recommended for those who have lost immunological memory. Receiving booster immunization at the age of 10-15 years may be more appropriate for individuals living in HBV high epidemic areas.

Early detection of unhealthy behaviors, the prevalence and receipt of antiviral treatment for disabled adult hepatitis B and C carriers

BACKGROUND

Evidence indicates that hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are the leading causes of liver cirrhosis and hepatocellular carcinoma. Antiviral treatments have recently been reported as successful cures. However, the prevalence rates of HBV or HCV infection, unhealthy behaviors and receipt of adequate treatment in disabled adults have not been described. The aim of this study was to examine the prevalence of HBV or HCV carriers, receipt of antiviral treatment, and early detection of unhealthy behaviors in disabled adults in Taiwan.

METHODS

A population-based, cross-sectional study was conducted between July and December 2013 with 845 community-dwelling adults with disabilities aged >20 years. Statistical analyses included descriptive statistics, Chi-squared tests, and stepwise regression analysis.

RESULTS

The prevalence of HBV and HCV infections was 12.9 and 14.1 %, respectively. HCV carriers tended to be older (p < 0.001) and with a lower education (p < 0.001). The majority of HBV/HCV carriers did not know the type of hepatitis infection and did not receive adequate antiviral treatment. After adjusting for potential confounding variables, regression analysis showed that the factors significantly associated with elevated liver function were HCV infection (p < 0.001), HBV infection (p = 0.001), high fasting blood glucose levels (p = 0.001), overweight (p = 0.003), older age (p = 0.027), and alcohol drinking (p = 0.028).

CONCLUSIONS

There was a high prevalence of HCV infection among adults with disabilities; few received adequate antiviral treatment or early detection of unhealthy behaviors for the prevention of liver cancer. Clinicians can provide health education to help the participants and caregivers better understand the relationships between specific risk factors and liver health and can encourage HBV and HCV carriers to undergo annual physical check-ups and receive adequate treatment, as covered by the national health insurance.

Slow decline of hepatitis B burden in general population: Results from a population-based survey and longitudinal follow-up study in Taiwan

BACKGROUND & AIMS

Hepatitis B virus (HBV) infection poses a global public health threat. HBV vaccination has proven highly effective in preventing the infection; however, its long-term impact on the general population has not been addressed. We conducted analysis to determine the total and changing burden of chronic HBV infection and evaluate the serological status between vaccinated and unvaccinated in Taiwan.

METHODS

Participants in "The Taiwanese Survey on Prevalence of Hyperglycemia, Hyperlipidemia and Hypertension" in 2002 (n=6602), and 4088 with follow-up survey in 2007 were included. HBsAg (including titers), anti-HBs, anti-HBc, HBeAg, anti-HBe, HBV genotypes and viral loads were assayed. Prevalence and evolving patterns of these seromarkers was compared between vaccinated and unvaccinated cohorts and predictors of persistent HBsAg positivity and negativity were examined.

RESULTS

The overall prevalence of chronic HBV infection was 13·7% (95% CI, 12.9% to 14.5%) and about two thirds had past exposure (anti-HBc: 68·46%) in 2002. The vaccinated cohort tended to have lower prevalence of HBsAg and anti-HBc, and a higher proportion of anti-HBs and HBeAg positivity, genotype C and high viral load. The majority (85·42%) were consistently HBsAg negative while 12·65% were consistently positive, and 8·98% achieved seroclearance in a five-year period. In the vaccinated cohort, no subjects had acquired new exposure and became HBsAg positive, and only one (0.54%) cleared HBsAg, demonstrating the durability of vaccination through teenage and young adulthood.

CONCLUSIONS

This comprehensive, population-representative-survey shows that 20 years after universal vaccination, the backlog still composed a substantial burden of chronic HBV infections in Taiwan.

SNP rs7770370 in HLA-DPB1 loci as a major genetic determinant of response to booster hepatitis B vaccination: results of a genome-wide association study

BACKGROUND AND AIM

Hepatitis B (HB) vaccination is highly effective in reducing the risk of hepatitis B virus infection. However, breakthrough and chronic hepatitis B virus infections in vaccinated subjects raised concern about its long-term efficacy. The specific aim of the study was to explore the host genetic determinants of long-term immunological memory against HB vaccination.

METHODS

We conducted a case-control study nested in a cohort of HB booster recipients who had received primary HB vaccination during infancy but failed to reside an anti-HBs titers ≥ 10 mIU/mL at the age of 15-18 years. We used a genome-wide single nucleotide polymorphism (SNP) array plate to scan autosomal chromosomes and assayed the human leukocyte antigen (HLA)-DPB1 genotype by sequence-based techniques.

RESULTS

We found that 10 of the 112 candidate SNPs (P-value < 5.0 × 10(-5) ) clustered within a 47-Kb region of the HLA-DP loci. All the minor alleles of these HLA-DP candidate SNPs were correlated with lower likelihoods of nonresponse to HB vaccine. There was a significant linkage disequilibrium between these HLA-DP candidate SNPs and HLA-DPB1 protective alleles. Multivariate analyses showed that rs7770370 was the most significant genetic factor. As compared with rs7770370 GG homozygotes, adjusted odds ratios were 0.524 (95% confidence interval, 0.276-0.993) and 0.095 (95% confidence interval, 0.030-0.307) for AG heterozygotes and AA homozygotes, respectively.

CONCLUSION

Our results showed that rs7770370 was the most significant genetic factor of response to HB booster. The rs7770370 and nearby SNPs may also contribute to the long-term immunological memory against HB vaccination.

Incomplete hepatitis B immunization, maternal carrier status, and increased risk of liver diseases: a 20-year cohort study of 3.8 million vaccinees

Hepatitis B immunization has been documented to prevent fulminant hepatic failure (FHF) and hepatocellular carcinoma (HCC) by historical comparison studies in Taiwan. This study aimed to assess long-term risks and predictors of various liver diseases associated with incomplete immunization in 3.8 million vaccinees. Profiles of the National Hepatitis B Immunization Registry, National Cancer Registry, and National Death Certification Registry were linked to ascertain newly diagnosed cases of HCC and deaths from FHF and chronic liver diseases (CLDs) from infancy to early adulthood of 3,836,988 newborn vaccinees. Cox's proportional hazards models were used to estimate hazard ratios (HRs) for various risk predictors. There were 49 newly developed cases of HCC, 73 deaths from FHF, and 74 deaths from CLDs during the follow-up of 41,854,715 person-years. There were striking differences between unvaccinated and vaccinated newborns after the launch of a national immunization program for HCC incidence (0.293 vs. 0.117 per 100,000 person-years), FHF mortality (0.733 vs. 0.174 per 100,000 person-years), and CLD mortality (2.206 vs. 0.177 per 100,000 person-years). Among vaccinees, incomplete immunization was the most important risk predictor of HCC, FHF, and CLDs, showing an HR (95% confidence interval, P value) of 2.52 (1.25-5.05; P = 0.0094), 4.97 (3.05-8.11; P < 0.0001), and 6.27 (3.62-10.84; P < 0.0001), respectively, after adjustment for maternal hepatitis B serostatus.

CONCLUSION

Hepatitis B immunization can significantly prevent the long-term risk of HCC, FHF, and CLDs from infancy to early adulthood. Incomplete immunization with hepatitis B immunoglobulin or vaccines was the most important risk predictor of the liver disease among vaccinees.

Report from a Viral Hepatitis Policy Forum on implementing the WHO Framework for Global Action on viral hepatitis in North Asia

BACKGROUND & AIMS

The World Health Organisation (WHO) Prevention & Control of Viral Hepatitis Infection: Framework for Global Action offers a global vision for the prevention and control of viral hepatitis. In October 2012, the Coalition to Eradicate Viral Hepatitis in Asia Pacific (CEVHAP) organised the North Asia Workshop on Viral Hepatitis in Taipei to discuss how to implement the WHO Framework in the North Asia region. This paper presents outcomes from this workshop.

METHODS

Twenty-eight representatives from local liver associations, patient organisations, and centres of excellence in Hong Kong, Japan, Korea, and Taiwan participated in the workshop.

FINDINGS

Priority areas for action were described along the four axes of the WHO Framework: (1) awareness, advocacy and resources; (2) evidence and data; (3) prevention of transmission; and (4) screening and treatment. Priorities included: axis 1: greater public and professional awareness, particularly among primary care physicians and local advocacy networks. Axis 2: better economic data and identifying barriers to screening and treatment uptake. Axis 3: monitoring of vaccination outcomes and targeted harm reduction strategies. Axis 4: strengthening links between hospitals and primary care providers, and secure funding of screening and treatment, including for hepatocellular carcinoma.

CONCLUSIONS

The WHO Framework provides an opportunity to develop comprehensive and cohesive policies in North Asia and the broader region. A partnership between clinical specialists, primary care physicians, policy makers, and people with or at risk of viral hepatitis is essential in shaping future policies.

Efficacy of hepatitis B vaccine boosters among neonatally vaccinated university freshmen in Taiwan

BACKGROUND & AIMS

Long-term protection against hepatitis B virus (HBV) after vaccination remains widely debated. We evaluated the efficacy of a modified 3-dose booster protocol in neonatally vaccinated university students in Taiwan.

METHODS

Changes in the levels of antibodies to the hepatitis B surface antigen (anti-HBs) were examined in 250 university students over a 3-year period. Group A (n=39) lacked seroprotective levels of anti-HBs, and declined to receive a booster dose of the HBV vaccine. Group B (n=128) lacked seroprotective levels of anti-HBs, and received booster doses of the HBV vaccine according to a modified 3-dose booster protocol. Group C (n=83) possessed seroprotective levels of anti-HBs, and did not receive a booster dose.

RESULTS

The levels of seroprotective anti-HBs increased in 12.8% of Group A and 14.5% of Group C, suggesting that our entire cohort had experienced booster effects from natural HBV exposure. However, no new HBV infections were observed, and 53.9% of Group B maintained protective levels of anti-HBs during the follow-up period.

CONCLUSIONS

The use of the modified 3-dose booster protocol induced significant long-term increases in the titer of anti-HBs in over 50% of the neonatally vaccinated participants with previously non-protective titers. However, in the absence of a vaccine booster, some neonatally vaccinated people with low anti-HBs titers may nonetheless produce anamnestic responses to HBV upon exposure, suggesting that protection from neonatal vaccination may persist, despite low titers of anti-HBs.

Significance and anamnestic response in isolated hepatitis B core antibody-positive individuals 18 years after neonatal hepatitis B virus vaccination in Taiwan

AIM

To investigate the significance of isolated hepatitis B core antibody (anti-HBc) and to analyze the response to hepatitis B virus (HBV) booster vaccination in young adults with isolated anti-HBc who had been fully vaccinated with HBV vaccine as infants.

MATERIALS AND METHODS

We screened 1734 new university entrants who had been fully vaccinated against HBV in infancy for the presence of hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and anti-HBc upon university entry. Results positive for isolated anti-HBc were reconfirmed by testing for the presence of HBsAg and anti-HBc once more, and further evaluated for anti-HCV, anti-HIV, and HBV DNA status 6 months later. Students were also offered HBV booster vaccinations at that time. Geometric mean titers (GMT) of anti-HBs after one booster dose of HBV were compared between students with isolated anti-HBc and students with HBV naïve status.

RESULTS

The overall prevalence of isolated anti-HBc in our student cohort was 1.2% (21 of 1734). No evidence of occult HBV infection was observed. A "booster" anamnestic response (anti-HBs titer ≥ 10 mIU/mL) was noted in 95% (20 of 21) of subjects with isolated anti-HBc. After re-measurement of anti-HBc, 13 (62%) of the 21 subjects with isolated anti-HBc were reclassified as having resolved HBV infection with a loss of anti-HBs. In the remaining 8 subjects (38%), isolated anti-HBc was determined to be false positive. The HBV status of these 8 subjects was HBV naïve due to the waning-off effect of anti-HBs of the neonatal HBV vaccination. There was no significant difference in anamnestic response to a single HBV booster dose of vaccine between students with isolated anti-HBc (n=13) and those with HBV naïve (n=323) status (GMT 50.6 vs 47.7 mIU/mL, P=0.90).

CONCLUSION

The presence of isolated anti-HBc 18 years after HBV vaccination can be attributed to post-HBV infection with a loss of anti-HBs and to a decline in anti-HBs elicited by vaccine. A single HBV booster dose of vaccine is recommended for subjects with isolated anti-HBc who were fully vaccinated with HBV vaccine as infants. This finding needs to be replicated in further studies with larger cohorts.

Seroprevalence of hepatitis B and C infection markers among children and adolescents in the southern Brazilian region

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections account for a substantial proportion of liver diseases worldwide. The aim of this study was to determine the prevalence of HBV and HCV serological markers among children and adolescents and verify the epidemiology of the HBV infection over than a decade of the introduction of vaccination program. Serologic markers to HBsAg, total anti-HBc and anti-HCV had been tested in 393 samples. The seropositivity for HBsAg was 0.76% and for total anti-HBc was 1.02%. Copositivity between HBsAg and total anti-HBc was verified in 0.76% of the analyzed samples. There was no seropositivity for anti-HCV marker. The seroprevalence of HBV infection markers among children and adolescents in the southern Brazilian region is high compared to that reported in other countries. Preventive measures, such as educational activities in addition to the universal childhood HBV vaccination, should be initiated in order to reduce the morbimortality and the economic burden associated with the disease.

Acquirement and disappearance of HBsAg and anti-HCV in an aged population: a follow-up study in an endemic township

BACKGROUND

HBsAg and anti-hepatitis C virus (anti-HCV) are stable markers and widely used. The seroconversion and seroclearance of HBsAg and anti-HCV are important for disease control and prognosis of diseases.

AIMS

To investigate acquirement and disappearance of HBsAg and anti-HCV in an endemic area.

METHODS

Seven years after a community screening, 1002 of 2909 residents of Tzukuan Township were recruited. HBsAg, anti-HCV and alanine transaminase (ALT) were checked in all who participated and hepatitis B virus (HBV) DNA, anti-HBs, anti-HBc, HCV RNA, anti-HDV and upper abdominal ultrasonography were studied in different groups.

RESULTS

There were 461 male and 541 female residents with a mean age of 66.7 ± 8.6 years. No new HBsAg carrier was noted and the HBsAg clearance rate was 1.58% per year. One of the 17 cases with HBsAg clearance had positive HBV DNA, three had ALT elevation, two had cirrhosis and seven had anti-HBs seroconversion. Quantitative of HBsAg and HBV DNA were concordant and 78.1% subjects had low levels of titration. Anti-HBc alone contributed to 32.1% and was prominent in old age and the anti-HCV-positive group. The anti-HCV seroconversion rate was only 0.74% per year and household transmission was the only risk factor. Only 37.5% of cases with anti-HCV seroconversion had HCV viraemia and the anti-HCV seroreversion rate was 0.63% per year. The anti-HDV seroconversion rate was 0.72% per year and no subject showed anti-HDV clearance.

CONCLUSIONS

Much higher rates of HBsAg seroclearance, anti-HCV seroreversion and anti-HBc alone were noted in this endemic area and no subject showed anti-HDV clearance.

Anti-HBs levels among children and adolescents with complete immunization schedule against hepatitis B virus. A cross-sectional study in Blumenau, State of Santa Catarina, Brazil, 2007-2008

INTRODUCTION: Vaccination is the main tool for preventing hepatitis B virus (HBV) infection; however, following the completion of the vaccination series, the concentrations of anti-HBs can decline over the years and reach levels less than 10mIU/mL. The persistence of protection in these individuals is still unknown. The present study aimed to determine the anti-HBs antibody levels among children and adolescents who had received a complete vaccination course for hepatitis B. METHODS: Antibodies against HBV surface antigen (anti-HBs) were tested in 371 individuals aged 10 to 15 years-old. RESULTS: Volunteers who showed undetectable quantities of anti-HBs accounted for 10.2% of the population studied and 39.9% presented antibody titers of less than 10mIU/mL. Anti-HBs ≥ 10mIU/mL were verified in 49.9%. CONCLUSIONS: These results corroborate other studies indicating levels of anti-HBs below 10mIU/mL in vaccinated individuals. Additional studies are required to assess whether this indicates susceptibility to HBV infection and the need and age for booster doses.

Efficacy of the nationwide hepatitis B infant vaccination program in Taiwan

BACKGROUND

Taiwan launched a nationwide infant vaccination program for hepatitis B (HB) in 1984.

OBJECTIVES

This study evaluated the seroprevalence of hepatitis B virus (HBV) and the incidence of high alanine aminotransferase (ALT) level among young adults prior to, during, and since the introduction of the nationwide HBV vaccination program.

STUDY DESIGN

Researchers recruited 101,584 freshmen (male:female=1.114:1; mean age, 18.5±0.5 years) from 21 universities between 1995 and 2009 (birth cohorts 1977-1991) in Taiwan, testing for serum hepatitis B surface antigens (HBsAg), hepatitis e antigens (HBeAg), antibodies against HBsAg (anti-HBs), and liver function tests, including ALT and aspartate aminotransferase (AST).

RESULTS

The results showed that the prevalence of HBsAg decreased significantly from 14.3% in 1995 to 1.1% in 2009 and the seroprevalence of HBeAg decreased significantly from 5.9% in 1995 to 0.3% in 2009. Seroconversion to anti-HBs maintained a steady rate above 50% between 1995 and 2007, but declined considerably to 36.6% and 36.4% in 2008 and 2009, respectively. Subject with HBeAg seropositivity was in 43.94% of HBV carriers. Double seronegativity for HBsAg and anti-HBs was observed in 2007 (47.8%), 2008 (62.3%), and 2009 (62.5%). High ALT level was observed in 5.74% of the subjects, particular among HBV-carriers (16.5% of HBV carrier vs. 5.0% of non-HBV carrier; ORs, 3.733; 95% CIs, 3.463-4.023, p<0.0001). Subjects with high ALT level were significantly positively associated with HBeAg (10.5% of HBeAg seropositive vs. 1.9% of HBeAg seronegative; ORs, 6.195; 95%CI, 5.629-6.818; p<0.0001). Male subjects were more easily infected by HBV than female subjects were (HBsAg, ORs, 1.355, 95% CI, 1.283-1.431; HBeAg, ORs, 1.324, 95% CI, 1.218-1.439, p<0.0001), and significantly more male subjects had high ALT levels than female subjects did (ORs, 4.087; 95% CI, 3.819-4.375, p<0.0001).

CONCLUSIONS

The mass vaccination program successfully reduced the HBV carrier rate and prevalence of chronic hepatitis B in Taiwan. However, the low percentage of anti-HBV in 2008 and 2009 remains unresolved.

Waning immunity and booster responses in nursing and medical technology students who had received plasma-derived or recombinant hepatitis B vaccine during infancy

BACKGROUND

The national hepatitis B virus (HBV) vaccination program was launched in Taiwan in 1984. After November 1992, a recombinant HBV vaccine replaced the plasma-derived HBV vaccine.

METHODS

A total of 1,812 nursing and medical technology freshman students was tested to evaluate their waning immunity toward hepatitis B. In the 2007 (2008) academic year, 438 (382) students testing nonprotective antibodies received 3 (1) booster doses of HBV vaccine according to suggestions from Taiwan's Center for Disease Control (CDC).

RESULTS

The seroprevalences of hepatitis B surface antigen (+) were 0.8% and 0.7% in the plasma-derived and recombinant group, respectively; for antibody to hepatitis B surface antigen (anti-HBs) (+), they were 43.2% and 33.3% (P < .001), respectively. In the 2007 freshman group, 99.1% of the students previously vaccinated with plasma-derived HBV vaccine exhibited anti-HBs seroconversion. In the 2008 freshman group, the booster dose induced anti-HBs seroconversions of 92.1% and 95.9% in the students who had received the plasma-derived and recombinant HBV vaccine, respectively (P = .370).

CONCLUSION

Most students exhibited signs of immune memory after receiving the booster, regardless of having received plasma-derived or recombinant HBV. Only a small number of vaccinees lost their immune memory after 16 years, suggesting that some students might benefit from boosting before proceeding to clinical practice.

Hepatitis B immunity in adolescents and necessity for boost vaccination: 23 years after nationwide hepatitis B virus vaccination program in Taiwan

The first universal hepatitis B vaccination program for newborns in the world was launched in Taiwan in July 1984. Most studies on the effectiveness of hepatitis B vaccination focused on the seroprevalence of HBs Ag among children under 14 years old. Only few studies focused on the seropositivity of anti-HBs among adolescents aged 15-18 years old. The present study aimed to evaluate the impact of the nationwide hepatitis B vaccination program on the immunity to HBV infection and the necessity of boost among adolescents. In this study including eight annual seroprevalence surveys from 2000 to 2007, 2342 college entrants (1589 15-year-olds in group I and 753 18-year-olds in group II) and 1851 university freshmen (18-year-olds in group III) participated. Subjects identified anti-HBs, HBs Ag and anti-HBc negative were given boost three doses of HBV vaccine. The HBs Ag seroprevalence was 11.6%, 3.5% and 1.0% for participants who were born before 1984, 1984-1986 and after 1986. The anti-HBs-seropositive rates were significantly higher in group II (83.1%) than in group I (53.0%) and group III (53.5%). All 572 participants who were seronegative for anti-HBs, HBs Ag and anti-HBc became anti-HBs-seropositive after catch-up vaccination. It is concluded that the anti-HBs-seropositive rate decreased to 50% in 15 years after vaccination, and boost vaccination was 100% effective. The necessity and age for boost among anti-HBs negative adolescents and the timing of the first immunization should be further evaluated.

Seroprevalence of chronic hepatitis B virus infection among taiwanese human immunodeficiency virus type 1-positive persons in the era of nationwide hepatitis B vaccination

OBJECTIVES

We aimed to assess the impact of nationwide hepatitis B virus (HBV) vaccination program on the seroprevalence of HBV infection among human immunodeficiency virus (HIV)-positive persons in a country where most HBV exposure occurs during the perinatal period or in early childhood.

METHODS

Data on HBV surface antigen (HBsAg), anti-HBV surface (anti-HBs), anti-HBV core (anti-HBc), and anti-hepatitis C virus (anti-HCV) antibody were retrospectively collected from 3,164 HIV-positive and 2,594 HIV-negative persons between 2004 and 2007. Comparisons of serological markers of HBV and HCV were made between HIV-positive and -negative adults born before and after the implementation of the HBV vaccination program in Taiwan in July 1984.

RESULTS

Compared with HIV-negative persons, the adjusted odds ratio for HBsAg seropositivity was 1.100 (95% confidence interval, 0.921-1.315) among HIV-positive persons. Although the seroprevalence of anti-HCV antibody remained similar between HIV-positive persons born before and those born after 1984, the seroprevalence of HBsAg declined from 20.3 to 3.3% in HIV-positive persons (P<0.001) and from 15.5 to 8.5% in HIV-negative persons (P<0.001). Despite the high seroprevalence of anti-HCV antibody (97.1%) in HIV-positive injecting drug users (IDUs), there was no statistically significant difference in the seroprevalence of HBsAg (5.6% vs. 8.5%, P=0.75) or anti-HBc antibody (40.7% vs. 27.9%, P=0.14) between HIV-positive IDUs and HIV-negative persons who were born after 1984.

CONCLUSIONS

Our study showed a significant decline of seroprevalence of HBV infection among both HIV-negative and -positive persons who were born in the era of the nationwide HBV vaccination in Taiwan.

HBV infection in indigenous children, 20 years after immunization in Taiwan: a community-based study

OBJECTIVES

Hepatitis B virus infection is hyperendemic in Taiwan. In the past, the infection rate has been higher in indigenous villages. The prevalence of chronic HBV infection among indigenous children after immunization remains unknown.

METHODS

A total of 843 indigenous children were checked for the hepatitis B seromarker. Another 606 metropolitan children were enrolled for comparison in 2005.

RESULTS

The seroprevalences (%) of HBsAg, (hepatitis B surface antigen) anti-HBs, (antibody to hepatitis B surface antigen) and anti-HBc (antibody to hepatitis B core antigen) among indigenous and metropolitan children were 3.2 vs. 0.17 (p<0.001), 47.4 vs. 51.2 (p=0.164), and 10.7 vs. 1.7 (p<0.001), respectively. Among the indigenous children, who were divided into three age groups, the prevalences of HBsAg and anti-HBc increased with age, while anti-HBs decreased significantly (p=0.025, 0.002, and <0.001, respectively). Children with positive HBsAg had a significantly higher mean (SD) age (10.2 (2.2) vs. 9.2 (2.1) years, p=0.024) and a higher ALT value (16.4 (8.0) vs. 10.6 (8.3) IU/L, p=0.001). In a multivariable analysis, indigenous residency, older age group and abnormal ALT value were independent factors associated with positive HBsAg.

CONCLUSIONS

The seroprevalence of hepatitis B infection has obviously declined among indigenous children 20 years after mass immunization programs launched in Taiwan. However, it is still higher than that of metropolitan children. Higher rates of chronic HBV infection in the mothers might be one important explanation for this finding.

Changing aetiology of liver dysfunction in the new generation of a hepatitis B and C-endemic area: cross-sectional studies on adolescents born in the first 10 years after universal hepatitis B vaccination

BACKGROUND/AIM

Geographical variation in viral hepatitis infection complicates various levels of liver diseases. This study elucidates the changing aetiology of alanine transaminase elevation (ALT levels >40 IU/L) in a previously hepatitis-endemic township.

DESIGN/METHODS

Five cross-sectional screenings were performed on teenagers born from 1984 to 1993. We examined hepatitis B surface antigen (HBsAg), anti-hepatitis C virus (anti-HCV), ALT and body mass index, and additionally checked hepatitis B envelope antigen (HBeAg) for positive HBsAg and HCV RNA for positive anti-HCV. Teenagers with ALT elevation underwent an ultrasonography examination.

RESULTS

This study enrolled 1788 (93.7%) of 1909 students, discovering individual prevalence of HBsAg (6.3%), anti-hepatitis B core (anti-HBc) (15.5%), anti-HCV (2.2%), overweight (22.4%), obesity (12.8%) and ALT >40 IU/L (3.7%). HBsAg and anti-HBc prevalence declined with trends, while obesity increased with trends (P<0.001). Among 66 ALT-elevated teenagers, prevalence percentages of risk factors were HBsAg (22.7%), anti-HCV (1.5%), obesity (45.5%), HBsAg with obesity (7.6%) and anti-HCV with obesity (3.0%). Additionally, obesity showed predominance (85.7%) among aetiologies of teenagers with fatty livers (60.9%). The independently associated factors of ALT elevation included being male (odds ratio, 2.18; 95% confidence interval, 1.21-3.93), HBsAg (4.25; 1.06-17.13), HBeAg (7.24; 1.64-31.9), HCV RNA (29.03; 5.8-145.29) and obesity (16.5; 8.79-30.98).

CONCLUSION

In place of viral hepatitis, obesity is becoming the major aetiology of abnormal liver function among the young generation in a previously hepatitis-endemic area.

HLA and response to booster hepatitis B vaccination in anti-HBs-seronegative adolescents who had received primary infantile vaccination

To explore contemporarily genetic and non-genetic determinants of long-term immunological memory to hepatitis B (HB) vaccination, we conducted a case-control study nested in an adolescent cohort of booster recipients who had received primary infantile HB vaccination but with residual anti-HBs titers <10 mIU/mL at 15-18 years of age. High-resolution phenotypes of human leukocyte antigen (HLA)-A, -B, and -DRB1 loci were determined by sequence-specific oligonucleotide probe hybridization. After controlling for pre-booster anti-HBs levels, the absences of HLA-A*02 and -DRB1*08, simply expressed as A*02(-) and -DRB1*08(-), and the presence of B*15 were significantly associated with elevated risks of non-response (post-booster anti-HBs titers<10 mIU/mL) to booster vaccination. The adjusted odds ratios (ORs) were 3.85 (CI, 1.82-8.33), 4.55 (CI, 1.23-16.67), 3.59 (CI, 1.40-9.17), respectively. There was multiplicative synergism between A*02 and B*15 on the risk of non-response to booster vaccination. The multivariate-adjusted ORs for A*02(-)/B*15, A*02(-)/B*15(-), A*02/B*15, and A*02/B*15(-) haplotypes were 20.39 (p=0.0003), 3.29 (p=0.007), 1.32 (p>0.05), and 1.0, respectively. Recent cigarette smoking and/or betel-quid chewing was associated with a 12-fold risk of non-response to booster vaccination. Further comparisons between responders and adolescents who had undetectable post-booster anti-HBs titers (<0.1 mIU/mL) demonstrated similar results. Our results indicated that response to booster HB vaccination as well as long-term immunological responses to HB vaccination are closely related with host genetic factors, and probably modified by recent substance use.

Obesity and hepatitis B infection are associated with increased risk of metabolic syndrome in university freshmen

OBJECTIVE

To investigate the prevalence of metabolic syndrome and its associated risk factors in a cohort of university freshmen.

DESIGN

A cross-sectional study in a university health center in North Taiwan.

SUBJECTS

A total of 8226 students (mean age: 19.2+/-2.3 years) receiving pre-entrance health examinations and lifestyle questionnaires during the 2005-2006 academic year were recruited.

MEASUREMENTS

A fasting plasma glucose, lipids, uric acid and hepatitis B serology were measured for each subject. The prevalence of metabolic syndrome and its individual components were examined using the America Heart Association and National Heart Lung Blood Institute criteria. The risk factors for metabolic syndrome were identified using a multivariate logistic regression analysis.

RESULTS

The prevalence of overweight, obesity and metabolic syndrome was 12.7% (17.0% in men and 7.6% in women), 13.0% (18.4% in men and 6.4% in women) and 4.6% (6.4% in men and 2.4% in women). The risk for metabolic syndrome increased with an increase of body mass index and plasma uric acid level, and decreased with the vigorous physical activity and current alcohol drinking. Furthermore, as compared to subjects with seroprotective titers from hepatitis B vaccination (anti-HBs(+) and anti-HBc(-)), those without protective titers of anti-HBs after vaccination or without hepatitis B infection (anti-HBs(-) and anti-HBc(-)) had 34% higher risk for metabolic syndrome, and those with natural infection of hepatitis B (anti-HBc(+)) had 58% higher risk for metabolic syndrome.

CONCLUSIONS

Overweight, obesity and metabolic syndrome were more common among men than women in university freshmen. Hepatitis B vaccination with anti-HBs(+) was associated with a lower risk of metabolic syndrome as compared to anti-HBs(-). However, hepatitis B infection presented with anti-HBc(+) was associated with a higher risk of metabolic syndrome. The interplay between hepatitis B infection, hepatitis B vaccination and metabolic syndrome needs further investigation.

Short-term response to a booster dose of hepatitis B vaccine in anti-HBs negative adolescents who had received primary vaccination 16 years ago

We conducted a revaccination study to investigate the short-term response to booster hepatitis B (HB) vaccination in seronegative adolescents who had received primary infantile HB vaccination. A booster dose of recombinant HB vaccine was administered to 395 adolescents 15-18 years of age whose serum titers of antibody against hepatitis B surface antigen (HBsAg) (anti-HBs) were <10 mIU/mL. Seventy-seven percent of the booster recipients converted to anti-HBs seropositivity (postbooster titers> or =10 mIU/mL). As compared with adolescents who had undetectable prebooster anti-HBs titers (<0.1 mIU/mL), the seropositive rates and geometric mean titers (GMTs) of 2-month and 1-year postbooster were significantly higher for those of prebooster titers of 0.1-0.9 and 1.0-9.9 mIU/mL (all p<0.0001). Postbooster titers declined significantly more rapidly for those with undetectable prebooster anti-HBs titers than for those with prebooster titers of 0.1-0.9 and 1.0-9.9 mIU/mL. Our observations indicate that a booster dose of HB vaccine maybe unable to induce sufficient immunological response in adolescents who had undetectable residual anti-HBs titers.

Hepatitis B seroprevalence and anamnestic response amongst Taiwanese young adults with full vaccination in infancy, 20 years subsequent to national hepatitis B vaccination

The long-term protective effect of hepatitis B virus (HB) vaccination against HB infection and the necessity for routine booster vaccination in young-adult age subsequent to full HB immunization at birth remain issues of some debate currently. This study is aimed at evaluating the seroprevalence of HB infection and the response to HB booster vaccination amongst young-adult university students who had previously undergone full vaccination during their infancy. Eight hundred and forty-three subjects (mean age 18.7+/-0.4 years), 492 males and 351 females, with a complete HB vaccination during infancy were enrolled into this study. The prevalence of natural HB infection, chronic HB-carrier status, and HB-naïve group was, respectively, 4.1%, 1.4%, and 62.3%. Amongst 316 study subjects who were naïve to HB infection and had received one HB booster at time of university entrance health examination, 49.6%, 91.4%, and 97.5% of the participants with a serum anti-HBs level <0.1, 0.1 to <1.0 and 1.0 to <10.0mIU/mL prior to the booster vaccination, respectively, developed an anamnestic response (i.e., >/=10mIU/mL) to a booster dose of HB vaccine. Full implementation of national-wide HB vaccination program in 1986 has significantly reduced the incidence of HB infection and associated carrier rate in Taiwan. Approximately three-quarter of the subjects who were naïve to HB infection and had received one HB booster demonstrated an anamnestic response to a booster HB vaccine. The higher the anti-HBs titers remained for an individual subsequent to primary vaccination, the greater the anamnestic response observed. Additional long-term follow-up studies are needed for young adults initially vaccinated for HB in their infancy.

Seroprevalence of hepatitis B viral markers among freshmen--20 years after mass hepatitis B vaccination program in Taiwan

BACKGROUND/PURPOSE

The nationwide hepatitis B vaccination program in Taiwan was well known for its efficacy in reducing the carrier rate of hepatitis B and the morbidity and mortality of hepatitis B-related diseases among children. The aim of this study was to investigate the seroprevalence of hepatitis B 20 years after this program was implemented.

METHODS

A total of 7592 freshmen from one university in Northern Taiwan participated in this study during their school entry health exam in September 2003 and September 2004. Basic data including gender, birthday, family history and vaccination history of hepatitis B by self-reported questionnaire were collected. Hepatitis B serum markers, including hepatitis B surface antigen, antibody against hepatitis B surface antigen, and antibody against hepatitis B core antigen were all checked. The differences in the seroprevalence of hepatitis B between two groups of subjects born before July 1984 and after July 1984 were examined. Multiple logistic analyses were performed for identifying the odds ratio (OR) of family history and other variables for each hepatitis B serum marker.

RESULTS

Subjects born after July 1984 were found to have a lower rate of hepatitis B surface antigen of 2.2% (95% confidence interval [CI], 1.8-2.6%) vs. 7.4% (95% CI, 5.9-8.9%), and core antibody against hepatitis B of 6.7% (95% CI, 6.0-7.3%) vs. 23.5% (95% CI, 21.1-25.9%), but a higher rate of surface antibody against hepatitis B of 74.3% (95% CI, 73.2-75.4%) vs. 69.1% (95% CI, 66.5-71.7%) compared with those born before July 1984 (all p < 0.001). Subjects with a family history of hepatitis B had higher risk of being infected by hepatitis B (OR, 4.07; 95% CI, 3.18-5.12) and becoming carriers (OR, 7.26; 95% CI, 5.05-10.44) after adjustment for sex, age, birth year, and self-reported hepatitis B vaccination history.

CONCLUSION

The seroprevalence of hepatitis B surface antigen continued to decline 20 years after neonatal hepatitis B vaccination program. It is strongly recommended that those who have a family history of hepatitis B should receive early check-up of hepatitis B status after complete vaccination or closely follow up their hepatitis B status after neonatal hepatitis B vaccination.

HBV serological markers of vaccinated children in remote areas of Taiwan: Emphasis on factors contributing to vaccine failure

A serosurvey targeting Hepatitis B virus (HBV)-vaccinated children born between 1986 and 1998 was conducted in 2001 in remote Taiwanese villages where a 1993 serosurvey indicated high vaccine failure. The HBV S antigen (HBsAg) seropositive rate among vaccinees of 3-6-year-old children in 2001 was significantly lower than that of 1993 and was higher among children who had a delayed vaccination schedule and received the plasma-derived vaccine. Vaccine escape variants were more prevalent among recipients of recombinant HBV vaccine residing in Hualien. Our study highlights the importance of continued monitoring of vaccinees for incidence of HBV infection in order to refine future vaccination policy.

Ethnicity, substance use, and response to booster hepatitis B vaccination in anti-HBs-seronegative adolescents who had received primary infantile vaccination

BACKGROUND/AIMS

In this revaccination study, we explored the determinants of response to booster hepatitis B (HB) vaccination in anti-HBs-seronegative adolescents who had received primary HB vaccination 15-18 years before.

RESULTS

After controlling for prebooster anti-HBs levels, cigarette smoking, betel-quid chewing, alcohol drinking, and indigenous ethnicity were significantly associated with elevated risks of non-response to booster HB vaccination. The adjusted odds ratios (aORs) were 3.21 (CI: 1.33-7.84), 8.78 (CI: 2.03-37.94), 2.64 (CI: 1.15-6.02), and 2.46 (CI: 1.28-4.72), respectively. Among adolescents with undetectable prebooster anti-HBs titers, only indigenous ethnicity significantly associated with elevated risk, with an adjusted OR of 2.57 (CI: 1.20-5.54), of non-response to booster HB vaccination. On the contrary, the influences of cigarette smoking, betel-quid chewing, and alcohol drinking were restricted to adolescents with prebooster anti-HBs titers of 0.1-9.9mIU/mL. The corresponding multivariate-adjusted ORs were 5.70, 17.41, and 3.72, respectively. Adolescents who smoked cigarettes and chewed betel-quid were at highest risk of non-response (aOR, 25.3; CI: 2.97-215.7).

CONCLUSIONS

A booster dose of HB vaccine may be insufficient to induce immunological response in healthy adolescents who had undetectable prebooster anti-HBs titers or who were of Malay-Polynesian ethnicity. Responses to booster vaccination are probably modified by recent cigarette smoking and/or betel-quid chewing.